When producing cast metal parts today, there are a number of methods known in the prior art that allow such production, such as, for example, sand moulding, ceramic moulding, centrifugal casting, etc., but said means have several drawbacks, particularly in relation to the mass production of different parts and the associated economic cost, as well as the need to have several hard-to-store moulds.
For example, sand moulding has the main drawback of being scarcely versatile as regards the design, which is a huge limitation when producing parts with a high degree of specification. This type of moulding furthermore has the additional drawback of requiring a wooden model for obtaining the sand mould of the part to be produced, meaning that the wooden model will be permanent. This requires having a given storage space and furthermore has to be made with a parting line, i.e., it must be made in two parts.
Furthermore, the possibility of sand getting into the part must be considered, which makes it necessary to trim away the excess material, etc., so said method generates a considerable cost increment when it is chosen as the means for producing the parts.
Another known example in the prior art is the use of a ceramic mould using polystyrene moulds injected onto an aluminium mould or the like, whereby avoiding having to store the moulds once they are used, providing more efficient solutions for machining and for moulding unitary parts.
Once the polystyrene mould is obtained, ceramic application step starts, in which the polystyrene mould is impregnated with ceramic material to subsequently be dried at a given temperature, and said operation can be repeated as many times needed, depending on the specific needs for producing the part.
Centrifugal casting is generally used for casting parts having a surface of revolution and a simple geometry (such as, for example, balls, tubes, etc.) by means of using metal dies, and it has endless advantages, among which it is necessary to point out that it reduces possible volume defects occurring while casting, that no process for removing excess material is required, and that it is a much more energy-efficient process than the other mentioned processes, but in turn it has the main drawback being scarcely versatile for producing parts with more complex geometries.
Example of methods for obtaining parts from moulds is international patent application WO9717150, which describes a method of preparing a shell mould for moulding hollow parts, in which a layer of refractory material is applied on a pattern of flexible elastically deformable material. A shell or die reproducing a negative of the pattern of the elastic mould is thereby obtained. Said mould is removed once said refractory layer is applied based on its deformability due to its elastic properties. Then pouring steel into said shell together with centrifugation will allow reproducing the hollow part that was initially intended to be moulded.